The rivalry game between Marcos de Niza High and Corona del Sol high schools, both in Tempe, is typically a contentious affair. The possible ban on students in American-themed clothing was allegedly put in place because Corona administrators feared it could add racial connotations to an already tense atmosphere.

In a now-deleted article quoted by Breitbart, the student-run newspaper at Corona reported race has sparked incidents between the two schools in the past.

“This is not something that can be denied—past games, even as far back as over eight years ago, have showcased themes and chants that appeared racist or offensive toward Marcos [school]. The theme was changed to “Orange Out” after the administration decided it was best to avoid any possible offensive connotations the theme would have.”

In a deleted tweet to a student, the paper said students wearing “green, USA, flags, Trump, etc.” would not be permitted entry into the game. It stressed the clothing itself is not the issue, but the potential intent behind it.

In a letter to parents, Corona Principal Brent Brown said he expects students “to be respectful” and asked parents to discourage “inappropriate signs, chants or clothing.”

Tempe police said it will have extra officers and patrols in the area.

The game is scheduled to begin Friday at 7 p.m. at Marcos de Niza, located near Guadalupe and Rural roads.